怎样在DLL中使用数据模块(50分)

328xy · 2002-12-12

我写的DLL中一函数要调用数据库，应怎样在DLL加入数据模块，函数又该如何调用

zw84611 · 2002-12-12

试试动态生成。

328xy · 2002-12-12

如何动态生成呢

Xelloss · 2002-12-12

不需要阿 Dll的工程里面也可以创建Form的。

狄克 · 2002-12-12

关注

wqthai · 2002-12-12

你可以让EXE调用一个创建数据模块的输出函数阿，比如 exports   CreateDM,   FreeDM; 在Dll里实现这些函数就可以拉！

quiben · 2002-12-12

给出以前我作过的例子,该例子是调用一个Form,该Form可以访问MySQL数据库. {具体的实现单元} unit DllFormUnit; interface uses   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,   Dialogs, StdCtrls, DB, ExtCtrls, DBCtrls, Grids, ADODB, ComCtrls,   ShellCtrls, DBGrids,TConMySQLUnit; type   TForm1 = class(TForm)     Button1: TButton;     ADOQuery1: TADOQuery;     DataSource1: TDataSource;     DBGrid1: TDBGrid;     DBNavigator1: TDBNavigator;     Button2: TButton;     procedure Button1Click(Sender: TObject);     procedure Button2Click(Sender: TObject);     procedure FormCreate(Sender: TObject);   private     { Private declarations }   public     { Public declarations }   end; procedure ShowDllForm(AHandle:THandle;ACaption:String);stdcall; implementation {$R *.dfm} procedure ShowDllForm(AHandle:THandle;ACaption:String); var   DLLForm:TForm1; begin   Application.Handle :=AHandle;   try     DLLForm:=TForm1.Create(Application);     if DLLForm<>nil then     begin       DLLForm.Caption:=ACaption;       DLLForm.ShowModal;     end;   finally     DLLForm.Free;   end; end; procedure TForm1.Button1Click(Sender: TObject); begin   ADOQuery1.Close;   ADOQuery1.SQL.Clear;   ADOQuery1.SQL.Add('Select * from user');   try     TConMySQL.Create(ADOQuery1);   except     MessageBox(0,'shibai','info',MB_OK+MB_ICONINFORMATION);   end; end; procedure TForm1.Button2Click(Sender: TObject); var   StrFliter:String; begin   StrFliter:=InputBox(输入查询的关键字','请输入人名','');   if StrFliter='' then   begin     MessageBox(0,'Sorry','Info',MB_OK+MB_ICONINFORMATION);     exit;   end;   ADOQuery1.Close;   ADOQuery1.SQL.Clear;   ADOQuery1.SQL.Add('Select * from mytable where Name=:"StringFliter"');   ADOQuery1.Prepared;   ADOQuery1.Parameters[0].Value:=StrFliter;   try     TConMySQL.Create(ADOQuery1);   except     begin       MessageBox(0,'sorry','info',MB_OK+MB_ICONINFORMATION);     end;   end; end; procedure TForm1.FormCreate(Sender: TObject); begin   ADOQuery1.ConnectionString:='DefaultDir=;Driver={myodbc driver};DATABASE=mysql;UID=root;PWD=;SERVER=192.168.0.100';   DataSource1.DataSet:=ADOQuery1;   DBGrid1.DataSource:=DataSource1;   DBNavigator1.DataSource:=DataSource1; end; end. {Project文件} library DllFormProject; { Important note about DLL memory management: ShareMem must be the   first unit in your library's USES clause AND your project's (select   Project-View Source) USES clause if your DLL exports any procedures or   functions that pass strings as parameters or function results. This   applies to all strings passed to and from your DLL--even those that   are nested in records and classes. ShareMem is the interface unit to   the BORLNDMM.DLL shared memory manager, which must be deployed along   with your DLL. To avoid using BORLNDMM.DLL, pass string information   using PChar or ShortString parameters. } uses   SysUtils,   Classes,   DllFormUnit in 'DllFormUnit.pas' {TForm},   TConMySQLUnit in 'TConMySQLUnit.pas'; {$R *.res} exports   ShowDllForm; begin end. {调用单元} unit DllFormUnit; interface uses   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,   Dialogs, StdCtrls, DB, ExtCtrls, DBCtrls, Grids, ADODB, ComCtrls,   ShellCtrls, DBGrids,TConMySQLUnit; type   TForm1 = class(TForm)     Button1: TButton;     ADOQuery1: TADOQuery;     DataSource1: TDataSource;     DBGrid1: TDBGrid;     DBNavigator1: TDBNavigator;     Button2: TButton;     procedure Button1Click(Sender: TObject);     procedure Button2Click(Sender: TObject);     procedure FormCreate(Sender: TObject);   private     { Private declarations }   public     { Public declarations }   end; procedure ShowDllForm(AHandle:THandle;ACaption:String);stdcall; implementation {$R *.dfm} procedure ShowDllForm(AHandle:THandle;ACaption:String); var   DLLForm:TForm1; begin   Application.Handle :=AHandle;   try     DLLForm:=TForm1.Create(Application);     if DLLForm<>nil then     begin       DLLForm.Caption:=ACaption;       DLLForm.ShowModal;     end;   finally     DLLForm.Free;   end; end; procedure TForm1.Button1Click(Sender: TObject); begin   ADOQuery1.Close;   ADOQuery1.SQL.Clear;   ADOQuery1.SQL.Add('Select * from user');   try     TConMySQL.Create(ADOQuery1);   except     MessageBox(0,'shibai',Info'',MB_OK+MB_ICONINFORMATION);   end; end; procedure TForm1.Button2Click(Sender: TObject); var   StrFliter:String; begin   StrFliter:=InputBox('请输入','人名','');   if StrFliter='' then   begin     MessageBox(0,'sorry','info',MB_OK+MB_ICONINFORMATION);     exit;   end;   ADOQuery1.Close;   ADOQuery1.SQL.Clear;   ADOQuery1.SQL.Add('Select * from mytable where Name=:"StringFliter"');   ADOQuery1.Prepared;   ADOQuery1.Parameters[0].Value:=StrFliter;   try     TConMySQL.Create(ADOQuery1);   except     begin       MessageBox(0,'sorry','info',MB_OK+MB_ICONINFORMATION);     end;   end; end; procedure TForm1.FormCreate(Sender: TObject); begin   ADOQuery1.ConnectionString:='DefaultDir=;Driver={myodbc driver};DATABASE=mysql;UID=root;PWD=;SERVER=192.168.0.100';   DataSource1.DataSet:=ADOQuery1;   DBGrid1.DataSource:=DataSource1;   DBNavigator1.DataSource:=DataSource1; end; end.

328xy · 2002-12-12

我想用下面的dll函数返回数据库中的一个值 Function Test(AHandle:THandle)

char;stdcall; begin   Application.Handle:=AHandle;   DataMode.Create(Application);   DataMode.ADOQuery1.SQL.Add('select * from ItemTable');   DataMode.ADOQuery1.Open;   Result:=Pchar(DataMode.ADOQuery1.FieldByName('F2').AsString);   DataMode.Free; end; 主程序调用： Function Test(AHandle:THandle)

Char; Stdcall;external 'jdcl.dll'; {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); Var S:string;     V:Integer; begin   S:=Test(Application.Handle); end; 报什么存取错误，正确的调用方法应该为什么

328xy · 2002-12-13

328xy · 2002-12-14

有谁知道啊

328xy · 2002-12-14

wqthai所说的CreateDM,  FreeDM应该怎样写呢？

晨晨 · 2002-12-14

不是太明白你的问题，如果，我猜，你是想写一个DLL，并且DLL中包含TDataModule 那么直接可以用，你点那个New图标就可以了。 如果你是想使用主程序中的TDataModule，那也许你应该写个函数把TDataModule传过去。 猜的。。。。[

]我半年没有写程序了

Xelloss · 2002-12-16

>>   Application.Handle:=AHandle;   DataMode.Create(Application);   DataMode.ADOQuery1.SQL.Add('select * from ItemTable');   DataMode.ADOQuery1.Open;   Result:=Pchar(DataMode.ADOQuery1.FieldByName('F2').AsString);   DataMode.Free; 你创建DataMode的方法不对吧。 试试DataMode := TDataModule.Create(self);

wqthai · 2002-12-16

哥们：我想得和328xy一样。。 能不能用你试试啊！

怎样在DLL中使用数据模块(50分)

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